The present invention relates generally to animal feeding devices, and more particularly to a sow feeding device which reduces feed wastage and sow injury.
Animal feeding devices are commonly designed to include an enclosed feed storage hopper, a feeding trough and an actuable means for transferring feed from the hopper to the trough. Variously effective sow feeder designs have been described. For example, Taylor, I., et al., Nat'l. Hog Farmer, 33:24-28 (1988), studied ten sow feeder designs and observed feed wastage ranges of from as high as 1 to 38% to as low as 0.1 to 8%. A 1% feed wastage is estimated to amount to over 1 ton of feed wasted per 100 sows per year. The authors also noted differences among feeders in terms of injury to the animal, and injury and inconvenience to the herdsman.
Some designs cause feed bridging and lodging in the passage ways of the feeder resulting in excessively slow feed flow, feed contamination, spoilage, and wastage. Certain feed-delivery mechanisms are overly intricate and cause feed to jam within the throat of the hopper causing erratic feed delivery. Where a feeder does not have an effective way to slow feed flow, the more feed put before the sow at any one time, the greater the chance for feed wastage as the sow roots around and carries feed out on its snout. For some designs, any moisture present in the trough can be wicked up the feed-delivery column causing feed to "set-up" and necessitating disassembly of the unit. Other feeder designs feature actuable mechanisms that are susceptible to corrosion by moisture, by salt in the feed, by animal saliva and manure acids and/or require continual maintenance.
Certain feeding devices do not "fit" most sows and as a result the sows tend to "throw" feed everywhere as they feed. For some designs, feed rooted around in the feeder tends to fall back to an area inaccessible to sows. Confining, space-restrictive, shallow designs require a sow to jam its head down diagonally as it eats, leading to rubbing and raw spots on the brow and near the base of the ears. Very restricted access to feed, i.e., an entry area simply too small for many sows and a feeding surface too deep, can lead to severe abrasions of the sow's snout, brow, and jowl. Further, those mechanisms with protruding rods and the like, can rub the sow's jowl as the sow pushes into the feeding device; also, these rods can trap substantial amounts of feed making it inaccessible to the sow and resulting in additional feed wastage. Exposed sharp edges, along with exposed bolt heads, can also lead to injury especially with very anxious or large sows.
Even the least wasteful feeding device studied by Taylor, I., et al., supra, resulted in feed wastage of from 0.1% to 8%. This device, manufactured by Farmweld, Inc., P.0. Box 532, Teutopolis, Ill. 62467, utilizes a hollow agitator pipe to dispense feed. Although the pipe slows feed delivery to the sow, it can jam in the throat of the hopper, either in the up or down position, and can cause erratic feed delivery. Also, feed can accumulate within the hollow of the agitator pipe thereby reducing the pipe's range of displacement until little or no feed can be delivered. This is a particular problem with diets having a relatively high fat or oil content, having a high moisture content and/or having a small particle size (i.e., fine grind). Yet, another disadvantage associated with the mechanism of this device is that when the feed hopper is completely full, the entirety of the feed weight rests on the pipe that must be lifted by the sow to dispense feed. For some sows, this excessive weight presents considerable difficulty and poses an additional risk of injury to the snout. Another shortcoming of this device is that the overall internal dimensions are not sufficiently large to completely accommodate the sow; although some of the internal 90.degree. angles have been eliminated with the addition of extra panels and converted to 45.degree. angles, it is still difficult for some sows to maintain complete access to feed trapped in the recesses of the trough. Furthermore, use of this device by larger or more anxious sows sometimes leads to distortion of susceptible metal panels and the eventual concomitant failure of the feed delivery mechanism.
Another commercially available feeding device is the Sow Saver Feeder, manufactured by Sollars Bros., Inc., 309 South Main Street, Washington Court House, Ohio 43160. This device utilizes a feed dispensing mechanism involving a roller tube which, when activated by the sow's snout, displaces a hinged agitator. The agitator, which also serves as the hopper bin bottom, keeps feed from bridging and serves as a guide for the roller. Because the device has a taller hopper bin to contain larger quantities of feed, a baffle plate is required to reduce the weight of the feed on both the agitator and on the roller tube. Accommodating differences among sow feeding patterns nessitates the addition of a further "feed drop control" mechanism. However, the mechanism must be removed from the feeding device to accomodate those sows incapable of using the mechanism. Also, from a maintenance and hygiene standpoint, the shape and means of forming the bowl area, the use of open riveted seams and the cavities and blind corners created by this combination, along with the intricate nature of the feed delivery mechanism, result in areas that are difficult to thoroughly clean and that may harbor pathogenic organisms.
Thus there continues to exist a need in the art for animal feeding device which reduce animal injury, minimize feed wastage and are convenient and safe for the herdsman.